/* Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.flowable.cdi.impl.context;

import java.util.Stack;

import org.flowable.engine.impl.context.ExecutionContext;
import org.flowable.engine.impl.persistence.entity.ExecutionEntity;

/**
 * @author Joram Barrez
 */
public class ExecutionContextHolder {

    protected static ThreadLocal<Stack<ExecutionContext>> executionContextStackThreadLocal = new ThreadLocal<>();

    public static ExecutionContext getExecutionContext() {
        return getStack(executionContextStackThreadLocal).peek();
    }

    public static boolean isExecutionContextActive() {
        Stack<ExecutionContext> stack = executionContextStackThreadLocal.get();
        return stack != null && !stack.isEmpty();
    }

    public static void setExecutionContext(ExecutionEntity execution) {
        getStack(executionContextStackThreadLocal).push(new ExecutionContext(execution));
    }

    public static void removeExecutionContext() {
        getStack(executionContextStackThreadLocal).pop();
    }

    protected static <T> Stack<T> getStack(ThreadLocal<Stack<T>> threadLocal) {
        Stack<T> stack = threadLocal.get();
        if (stack == null) {
            stack = new Stack<>();
            threadLocal.set(stack);
        }
        return stack;
    }

}
